


Why me?

by TheHolosexualPan



Series: Omegaverse AU [1]
Category: Haikyuu!!
Genre: Alpha Tsukishima Kei, Alpha/Beta/Omega Dynamics, Alpha/Omega, College, Established Relationship, First Time, Fluff, I Wrote This Instead of Sleeping, Light Angst, M/M, Mating Bites, Mating Cycles/In Heat, Omega Yamaguchi Tadashi, Oneshot, Porn With Plot, Smut, Somebody take my keyboard away from me, Tags Are Hard, Ya u read that right, Yama is an angsty baby who thinks he isn't worthy of being loved, pls, smex, so he doesn't want to get bonded with Tsukki, surprisingly, this was a commission
Language: English
Status: Completed
Published: 2018-01-12
Updated: 2018-01-12
Packaged: 2019-02-24 14:51:55
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 6,816
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13216119
Author URL: https://archiveofourown.org/users/TheHolosexualPan/pseuds/TheHolosexualPan
Summary: Tadashi knows, heknowsthat if he and Kei bond, Kei will be tied down to him and him alone, but he's not sure that that's what the alpha really and trulyneeds, even if Tadashi loves him more than words can describe.Keithinks otherwise.





	Why me?

**Author's Note:**

> I think this AU is going out of control, but hey, I'm enjoying myself so meh :p  
> The premise is that once you bond with someone, you can only start a family with that person in particular unless death occurs, yada yada, you get the spiel
> 
> Aaaand I'm trying my hand at smut again
> 
> Also, this happens between Scentless and Family so ya

 

Tadashi groaned softly as he raised his head from the soft pillow he had been peacefully sleeping on just a few moments ago, until he felt his phone buzz on the tiny nightstand next to the bed. Was it really that early already, Tadashi pondered, looking at the time. It was just 6:30, so he still had half an hour of sleep until he  _really_  had to get up.  
And so Tadashi turned back, settling into his earlier position, facing the empty side of the bed, where Kei slept.  
Tadashi _knew_ that the alpha had classes earlier today, but it was almost summer break! He could've... Could've...   
The omega sighed and chuckled a little bit at his own silliness. Tadashi shouldn't be that worried about what Kei did. He was a grown man, after all, an especially nicely grown man, his inner omega purred, but Tadashi just ignored that particular comment and buried his freckled face into the pillow again, delighted by how soft it felt. Kei also tended to use this very same article, made out of cotton and filled with fluffy material, so his boyfriend's scent was heavy on it.  
Drunkenness, was how Tadashi would describe the feeling that Kei's scent gave him during early mornings like these.  
But it also gave the omega a sense of security, like a safe embrace, the perfume of a crisp forest, that had just been beaten down with a heavy rain, but it wasn't just soil and trees and the specific smell of 'after-rain' that Tadashi felt, it was also something distinctively Kei, like the sweetness of the berries in that line forest and something that Tadashi just didn't really have the words to describe.   
It was very calming, nonetheless.

Tadashi smiled into the cotton and wrapped his arms around the pillow, hugging it to his chest tightly. Well, now he  _couldn't_ stay in bed. Not with all the thoughts about his mate going through his hea-  
No.  
Tadashi slowly got up, rubbing his shoulders a little as a small shiver of anxiety went through his body, from head to toe, making the tips of his fingers buzz.  
' _Kei isn't your mate, get over it, Tadashi_!', he told his inner omega, which now seemed to go into a sobbing fit.  
_'And it's for the better if I'm not his anyways, I mean, who would want to start a... a f-family with an omega like_ _ **me**_ _?',_  Tadashi continued in his mind. The boy tugged his shirt down, only to notice that it was Kei's. It hung on to his frame, and while Tadashi himself was not a no-muscle person, he  _was_ an omega, and compared to Kei, who was an alpha, there was definitely quite the difference in size.   
Tadashi found that he didn't really care much about the fact that the shirt looked more like a night gown on him and he was feeling so warm that he couldn't even be bitter about the fact that he had stopped growing after presenting, while the alpha just continued on for a few years after that.  
But it also brought a string of pain, that thought. Because he was thinking about how much he wanted to be bound to Kei, but he couldn't...  
The alpha should have the option to choose someone better, not pathetic, little Tadashi, who was barely anyone noticeable. Actually, the omega wasn't even sure about  _why_ the alpha was dating him anyways, but Tadashi simply couldn't bear the thought of them not being in a relationship, not after so long, after he'd grown so attached to him. He knew that Kei had proven time and time again how much he cared for Tadashi, but...

...but his insecurities were never something he had a lot of control over, even if he was better now than his all-time low in high school.  
With a sigh, the boy went on with his day. After all, if he wanted to be worthy of Kei, to be someone better for himself, than he couldn't just mope around in bed all day, hoping things would magically change.

And if there was one thing Tadashi prided himself for, it was the fact that he was actively trying to be a better person, a better boyfriend for Kei, and at least he had that going for him.  
Even if he and Kei were never going to be mates and even if Tadashi'd have to go through Kei finding someone else to build a family with, at least Tadashi tried.  
A small sniffle escaped from Tadashi's lips as he got dressed and ready for his courses, but he ignored it and just left through the door a couple of minutes later.

 

* * *

 

 

  
When the week finally ended, Tadashi couldn't be happier. His grades were good, so his scholarship was not in any danger, at last he could sleep more, which was always an advantage in his eyes. Also, he could finally get off of those heat suppressants, which he never really liked much. The pills were bitter and gave Tadashi a lot of headaches, so it was about time to finally stop taking them, at least for a while.

Kei was waiting at the gate of Tadashi's college, leaning onto the porch with a casual pose, checking his phone while he presumably waited for his boyfriend.  
Tadashi smiled widely and ran towards the waiting alpha. With a loud and excited "Tsukki!", he jumped into the other's arms.  
Kei just clicked his tongue as he raised Tadashi off of his feet and held him to his chest, hands strong around the omega's waist. But there was a grin on his face, small, maybe, but Tadashi had learned to read Kei after knowing him for so long.  
That was another thing he prided himself into.  
"Well, aren't you happy to see me, huh?", Kei spoke as needed nuzzled into Tadashi's greenish hair.   
Tadashi could purr at the contact, but they were in public, so he merely nodded excitedly and reached his hands around Kei's neck to run freckled fingers through pale blond hair.  
The alpha took in the boy's scent, inhaling deeply. However, his small smile from before soon turned into a frown. He was probably mistaken...  
Right?

"Hey, Tadashi...", Kei mumbled, sniffling some more, almost sure of his earlier assumption now.  
"Hm~?"  
"Did you already stop taking your surppessants...?"  
A few beats passed in complete silence. And then Tadashi laughed again, albeit a bit more sheepish than before.  
"Yeah, but it's vacation already, s-so it's all good, right?"  
Tadashi tried to keep his voice down, but it was obvious that he was a lot more nervous now than before. After all, he didn't want to upset Kei, not after finally coming to terms with them not going to ever be together like... Like  _that_ _just a few days ago._  They weren't going to be mates...  
_'Ok, get ahold on yourself, Tadashi! We've gone through this before!!',_ the omega tried motivating himself. It was for Kei, so Kei could have a future that wasn't chained down to Tadashi, pathetic, old, boring Tadashi, Tadashi who was  _still_ scared of people that knew how to seem intimidating, Tadashi that still couldn't ever quite speak without stuttering a bit every so often, Tadashi who looked boring in general, but as an omega, was literally, in his eyes, everything an omega shouldn't be.  
Old, boring, pathetic YamaguchiTadashi...

"-shi. Tadashi", Kei mumbled, trying to snap the boy out of his dazed state. The omega raised his gaze from the ground, dark green eyes looking at Kei with an almost confused shine in them.  
"Y-yeah...?", Tadashi asked slowly, clearly trying not to worry the alpha by putting a forced smile on his face and a fake cheeriness in his voice.  
Kei sighed and just squeezed Tadashi to his chest once more, trying to wordlessly reassure his boyfriend that whatever it was that he was worrying about this time was going to turn out to be fine.  
Tadashi gave a small hum but quickly broke the hug off, only to grab Kei's hand and start hurrying the both of them towards the train station. It wasn't really in character for the brunet to do so, but maybe it was because of the coming heat, Kei reasoned.  
So he followed silently, for now. But there was something off about Tadashi today, and it wasn't something that had to do with his omegan biology.  
More like something to do with Tadashi's thoughts...

He hoped Tadashi was fine. Kei couldn't help but be worried about  _his_ omega.

 

* * *

 

 

The ride home was peaceful mostly, and Tadashi was kind of proud of himself because for once he had managed not to start rambling about his day.  
_'That has to get annoying after a while, so it's better like this...'_  
Tadashi did, not surprisingly, start feeling sleepy, so at one point he had ended up leaning his head on Kei's shoulder.  
He'd berate himself for that later, but right now, Tadashi let out a small satisfied breath, feeling the other's warmth and hearing regular heartbeats.  
Tadashi blamed Kei's relaxing pheromones for falling asleep, but he couldn't deny how good it felt to close his eyes a little in the presence of the one and only person who could calm Tadashi down at his most stressed, the person over whom his inner omega purred and cooed.  
It was simply inevitable, really.  
What he didn't expect, however, was to wake up in their bed, Kei spooning him from behind, the blond's nose buried into Tadashi's neck, tickling the scent glands found there.

It was just instinct that the omega let out a small mewl at the sensation.

 

* * *

 

 

Kei let the brunet use his shoulder as pillow for now. Tadashi always had problems getting properly rested before a heat, and even with suppressants, he'd still wake up with bags under his eyes and headaches. Kei really felt sorry for his boyfriend, but in a way, he could see why that might be. After all, omegas should sleep more before a heat, whether that heat would actually occur or not was another matter. So of course, for the comfort of the one he loved, Kei risked a few giggles from other people on the train and a few tilted heads. After all, the boy's scent was faint (which Kei appreciated, actually, since other alphas wouldn't approach  _his_ boyfriend) and it seemed that he was still either unpresented or a beta, plus Tadashi didn't really look like on omega at first sight, all tall and lanky limbs, while definitely not as big as Kei himself, Tadashi was just unusual when it came to looks. Of course, it was only Kei that knew how pretty Tadashi really looked after those first glances, and in a weird way, that thought really made him feel a bit smug. No one would know just how pretty and perfect Tadashi was. And that means that no one will try and still him away from Kei.

Maybe it was mean of him to not want others to look at Tadashi, but at the same time, it made his alpha instincts go wild. Sometimes, the possessiveness that came with being an alpha scared Kei, but he didn't mind, really.  
Tadashi had helped him control all the actions those feelings might evoke, so he knew that it wouldn't really harm anyone if Tadashi just stayed Kei's and Kei's only.  
_'Still, why_ _is_ _alpha biology so weird...? I shouldn't be so possessive. He's not even my mate...',_  Kei thought.

But he wanted Tadashi to be his mate, so badly. They had been dating for years now, had been friends for even longer. They were always there for each other, so why weren't they together like that?  
Kei hummed.  
They should discuss this soon, if Tadashi's heat was already on its way.

Kei's mother would definitely be happy that they'd finally crossed that certain threshold, but it was Tadashi's alpha mother that the blond was worried about. She was more of a traditional thinker. She hadn't been happy to know that Kei had been there for Tadashi's heats, even if they'd never done anything more than making out and maybe some rutting against each other, before the two got married.  
Honestly, Mrs. Yamaguchi was a much scarier alpha than Kei could ever hope to be, and he could see why she turned out the way she did.  
After Tadashi's dad left them, it was just the two of them and she was the only one Tadashi could rely on. Kei guessed he'd also be way more protective of his hypothetical children if they got bullied by others, but still...  
It wasn't as though Kei was just planning to get into Tadashi's pants and then go away. If that had been his intention, than he'd have done so when the omega first presented and Kei stumbled upon him, the boy begging for Kei to take him right then and there.  
But he could see where she was coming from.  
Yeah, they definitely had to talk once they got home...

Kei was roused from his thoughts as the train finally reached their destination. He looked down at the lump that was the sleeping omega.  
_'I should.. I should wake him up...'_ _,_ he thought.  
It was the logical thing to do, really. After all, they were close to home at this point anyways and it was already pretty hot outside, which meant that if Kei was to carry Tadashi, both of them would probably end up as a sweaty mess. Which, maybe in another context, he wouldn't really mind-  
Kei shook his head.

But of course, life isn't that simple, and approximately two minutes later, the alpha found himself carrying the shorter boy down the street towards their tiny apartment.

 _'Goddamnit self...'_ , Kei thought. But he didn't really mind. No, this was a pretty good excuse to keep the omega as close as possible to his body, inhaling the sweet scent. With a small sniff, Kei could tell that Tadashi's heat was right around the corner. Hopefully, the omega could get at least a couple more hours of sleep before that happened. The alpha knew how exhausting this entire ordeal was for Tadashi, even more so because he had presented late.  
Kei hoped that this time around, he could actually  _be with_ Tadashi through his heat, because after years of refraining, Kei's patience was slowly wearing thin. But alas, he'd never force himself onto Tadashi, no matter how much he desired him.

A few minutes later, the two were finally in the safety of their home, and Kei's eyes were a bit darker. Well it wasn't really his fault, now was it? Tadashi's heats were always a bit surprising to both of them. Sometimes, Kei could tell precisely when Tadashi would go into heat with a mere sniff if his boyfriend's scent, but other times, like right now, for example, Tadashi's biology would suddenly kick the speed of its reactions up a notch.  
But it wasn't the most tragic thing ever. At least now they were home, where Tadashi could be relaxed about himself and Kei could make sure that the omega was taken care if during his most vulnerable moments.

Tadashi didn't seem to be waking up any time soon, so Kei simply walked to their bedroom, arms already a bit tired and shirt clinging to his skin from the sun outside.   
Once their bed came into view, the alpha laid his boyfriend onto it, making sure Tadashi was as comfortable as possible, even going as far as placing his pillow in Tadashi's arms, knowing that the omega was always calmer if he could feel Kei's scent as soon as he woke, especially if he was approaching a heat.  
With a small sigh and a kiss on Tadashi's forehead, Kei left the room, closing the door quietly on his way and running a hand through golden strands.  
_'I feel as though this heat in particular will be so much more troublesome than all others...',_ Kei thought, pinching the bridge of his nose and taking his glasses of for just a moment, before he put them back and headed towards the kitchen, where he made sure that they had protein bars neatly packed and that all the groceries were put away.  
He knew this would be a long week, so might as well be prepared for it sooner rather than later, especially knowing how whiny Tadashi got during heats, and seeing as, this time around, Kei himself might actually be directly involved in taking care of his boyfriend, rather than comforting him and trying to stay out of their room when the waves of his heat would hit Tadashi like a tsunami.

Kei sighed once more and checked everything again before heading back to their bedroom. He opened the door slowly, as to not rouse the sleeping omega, and put his glasses on the bedside table. He sat on the bad, looking down at the freckled boy and admiring the way his face was fully relaxed, brow not creased, nose twitching every so often (something that Kei found adorable, even though he would never admit it) and plush lips half open, warm breath puffing out constantly.  
The alpha ran a hand down Tadashi's soft cheek, tracing the freckles lightly and smiling.  
His vision might be blurry, but even so, Kei still felt how velvety the tan skin was under his finger tips.  
A few moments later and Kei was finally laying down on the bed and scooping the omega into his arms, squeezing his slim waist to his own and letting out a single, content breath.

It was only moments later when Tadashi began waking up that Kei nuzzled his neck. He would call that action of his own instinct and he'd also call that the small mewl Tadashi let out as he opened hazy green eyes.  
"Did you sleep well, love?", Kei asked, hand massaging the hip underneath it.  
"Mh...", was the only response he got, but the omega seemed quite happy with their position, cuddling further into Kei, not really minding the fact that the warmth of Summer combined with the alpha's hot skin might be a bit uncomfortable. But Tadashi was always the type of person that had cold skin, so Kei concluded that it wouldn't really matter in the brunet's eyes.  
But then Tadashi froze up, as if suddenly remembering he had classes, but worse. Was it his heat? Kei had to ask, he wouldn't know for sure otherwise.  
"Did it already start...?", Kei asked gently, palm moving towards Tadashi's hand a gripping it into his own, even if it was a bit uncomfortable in their current position. Kei didn't really care much either way, if it was for his boyfriend's sake.  
"No... Not really... I think we have a few hours left", Tadashi hummed, body seemingly defreezing from its statue-like state.  
"Then? Is something bothering you, Tadashi?", Kei pressed on. He knew that Tadashi wasn't normally the type that would just open up about himself to others, but Kei was his boyfriend.  
"Ah, no, n-nothing! Sorry for making you worry, Tsukki!"  
'Ah, that phrase again...? It sure brings back memories, huh?', Kei thought, a small wave of nostalgia running through his body.  
"Shut up, Tadashi", he continued with a chuckle.  
Tadashi giggled a little, which was a good sign.

"Tadashi, we need to talk", Kei started again, sitting up on the bed, the other following his movements, face seeming worried. Kei wondered why that was. Maybe Tadashi also had something to tell him?  
"A-about what, Tsukki?"  
Sometimes, Tadashi still used 'Tsukki' instead of Kei outside of the teasing and the 'Shut up, Yamaguchi/Sorry Tsukki!' combo, especially when he was nervous or scared.

"I want to spend this heat with you."

 

* * *

 

 

Tadashi blinked once, then twice, eyes going wide before his brows furrowed in confusion.  
"But... You've... I've always spent my h-heats with you, Kei...", Tadashi responded softly.  
And then it hit him like a ton of bricks falling on top of him, crushing his stomach and knocking all the air out of his lungs.  
Tadashi blushed, almost from head to toe, it seemed, and he finally understood what Kei meant. He meant together- _together,_ as in, they should do  _it._

After gulping and taking a deep breath, trying to cool down his already hyper brain, that was running around in circles at the mere  _thought_ of him and the alpha doing that. It wasn't that Tadashi hadn't wanted to in the past, it's just that...  
' _When an alpha-omega couple spends their first hear/rut together, it is common that they also bond. This isn't a 100% scenario however, but the bond is much easier to make (and it is also easier to overwrite an already-existing bond too, as long as the alpha/omega's mate in question is either dead or has released them) after the two laying together for the first time, due to the body being most_ _maleable_ _during that time period.'_  
Tadashi remembered this explanation from one of the books he'd read on the dynamics, also known as secondary genders, before he had presented. So was Kei implying... That he... With Tadashi...

"You still there, dork?", Kei flicked Tadashi's forehead. With a small since and an offended "ow", Tadashi pulled back, laughing lightly.  
Kei's golden eyes were fixed on him and Tadashi couldn't help but imagine a certainly not PG-rated scene playing between the two lovers.  
"Just so you know", Kei cupped Tadashi's face, thumb stroking the freckled, red skin of the omega, "I'm not forcing you to have sex with me, but I, honestly, do not see a reason as to why not..."  
Tadashi bit his lip. He wanted to, oh how he wanted to finally sleep with Kei, wanted to feel the other, but...  
"I... Want you to be my mate. Will you be mine?"  
Kei pecked Tadashi's lips, light and almost innocent, at least when one listened to the context of their discussion.  
Would Kei care if Tadashi didn't leave a mark? He wouldn't, right? Honestly, Tadashi couldn't see himself with someone other than Kei, so he didn't care much if the alpha marked him.  
With a few more seconds of processing, Tadashi finally nodded, albeit a bit reluctantly.

 _'It's_ _fine, it's for his own good, he doesn't need you'_

Kei took Tadashi in his lap and started rubbing circles into his back, light patterns that usually haunted Tadashi's dreams at night.

Tadashi sighed, a certain calm taking over him, the kind that always appeared a few hours before his heats. His mind was somewhat at ease, although...

"Are you sure, baby?"  
Tadashi smiled at Kei and pecked the blond's lips with a small giggle.  
"Can we sleep a bit more, though? Pretty please?", Tadashi pleaded with his alpha, knowing that Kei never said no to his puppy face.

The pair cuddled back on the bed, this time with Tadashi burying his entire face in Kei's chest and the alpha taking in the brunet's sweet scent. Sweeter than usual because of the looming heat.  
A few beats passed before the two fell asleep, one due to a body that was preparing for high levels of exhaustion during the following week and the other due to his boyfriend's soothing scent.

~•~

When he finally woke up again, Tadashi knew exactly why he had done so. His skin felt like it was prickled by thousands of needles, but it felt...  _D_ am _n_ _it, it felt good!_  
His breathing felt like not a necessity, but a burden at the moment, seeing as the air around the room did nothing to help cool his skin down. And he could feel how damp the sheets had gotten from how much the one was sweating.  
Tadashi threw a glance upwards. It was... Dark already. But it still was too hot for him. He wanted to get up, but a sleeping Kei was keeping him from actually doing so, with a hand thrown haphazardly over Tadashi's waist, keeping him glued to the alpha.   
Tadashi whined, the scent if his boyfriend only serving to hear his body up even more. It  _hurt._  
Tadashi decided that he couldn't handle it any more, and as slowly as he could, what with his mind foggy and his body shacking, he peeled the arm that was trapping him off if his.  
With wobbly steps, Tadashi made his way towards the balcony of their bedroom, a small sigh escaping him as the cold, summer-night breeze hit his back, his legs and his face. It felt like heaven for the omega. For a moment, the brunet considered staying there, on the small balcony, until his heat passed, but then things took a turn for the better/worse as he felt a small pressure in his stomach and a wetness between his thighs.  
Rubbing his legs together, Tadashi felt a sliver of pleasure coarse through his veins and he fell to his knees, arm still holding onto the railing at the sensation.  
With his last powers, Tadashi called out in a meek voice, eyes half closed with lust and face completely red.  
"Kei... Kei...!"  
It took a few moments before Tadashi heard a groan and then his boyfriend's hurried steps as Kei made his way towards the balcony.

"Tadashi, why are you-", he didn't get a chance to finish as Tadashi jumped to his feet and basically knocked Kei and himself down onto their sift carpet, straddling the alpha with his hands around Kei's neck, panting softly.   
For just a moment, Kei seemed shocked, but as soon as he took a sniff of the omega's scent, his eyes darkened, a growl filling the small room as Kei gripped Tadashi's hips hard enough to bruise.  
"Alpha~", Tadashi whined as he ground his hips on Kei's own, throwing his head back in pleasure as he felt more slick leave his hole.  
With another almost animalistic sound, Kei pounced on Tadashi, turning them around and pinning Tadashi's hands above his head with one hand, the other literally ripping the omega's clothes off of his body.  
"Hngh...!", Tadashi closed his eyes when Kei bit onto his earlobe, laying kisses down the column of Tadashi throat and finally reaching exposed nipples that were now hardened oink nubs under Kei's ministrations.  
The alpha latched onto them and sucked,  _hard._  
_"_ A-ah! Kei~!", Tadashi moaned out.  
Kei finally got off of Tadashi's body, admiring just how ruffled his boyfriend looked after just a bit of touching. Oh, Tadashi was going to be a mess,  _simply a mess by the end if the night..._

Regaining a bit of consciousness, Kei caressed the side of Tadashi's freckled face, which was red and hot to the touch and grabbed Tadashi's thighs, directing the omega to wrap his own around Kei's neck, which he did without much complaining, although he did grind his hips against Kei, again.  
"Naughty boy", Kei whispered into Tadashi's ear, enjoying how the brunet shivered and kicking the shell of his ear, "I wanted to bring us to the bed, but you just couldn't wait for your alpha to wreck you, huh...?"  
Tadashi just let out another mewl and at that, Kei's eyes grew feral and he slammed the omega's into the nearest wall, smashing their lips together.  
The blond took advantage of Tadashi's surprised open mouth expression and simply shoved his tongue into his mouth.   
The sounds escaping the pair as they made out, of wet tongues sliding against each other, of teeth clacking together due to both of their desires for each other and heavy wanting, accompanied by Tadashi's loud shrieks and Kei's grunts.  
Kei could get hard simply by listening to the sounds the Omega was making, but with the pheromones Tadashi was emitting... It was too much, especially now that he had free reign and could actually do more than just help Tadashi get off.  
"K-ke-Mhhh...!", the omega whined, breaking the kiss, giving Kei the chance to attach himself to his neck.  
"What", he punctuated each of his words with another nibble to Tadashi's neck, leaving more and more hickeys in his wake, "Do you need, my precious, little omega...?"  
Tadashi swooned at the petname and looked at Kei's eyes, tears clinging to long lashes and lips red from kissing.  
"P-please... F-... Fuck me, alpha..."  
Kei simply snapped at that.

Maybe it was the fact that those few words were stuttered out in a weirdly shy tone. It's not as though they've never played with their words before, sometimes in a joking matter, other times through text during Tadashi's heats, but there was a fire in Tadashi's speech, and it made everything feel so much more real. It reminded Kei of what they were about to do, about the treshold they were about to cross, the barrier they were about to overcome. About how their relationship might change once they bonded.

But now was not the time to dwell on all those things, no, not when the omega under him looking up at him with big , lustful eyes and his freckled face covered in a red flush that extended past the collar of his shirt.  
"Are you sure, love?", he asked, voice as calm as possible and a gentle lul in the words he spoke as Kei nuzzled the side of Tadashi's neck. Tadashi's sweet scent, already heavy due to his heat, turned even sweeter at the touch.  
Tadashi couldn't moan out fast enough, small gasps desperate.

"Please... Please, Kei!", he breathed sharply out, taking Kei's face between trembling fingers. Without even waiting for an answer, the omega ground his hips against Kei's own, an action at which the alpha growled lowly.  
It was then that Kei's alpha said ' _fuck it'_ and Kei's instincts took control as he threw Tadashi onto the bed, crawling with a predator-like look on his face, golden eyes narrowed dangerously.

Tadashi shivered and simply started taking his clothes off, the room entirely too warm and his skin restricted under the material.  
Green meeting glowing yellow, Tadashi looked into Kei's eyes, and as soon as the omega only had his underwear on him anymore, the alpha, pinned his wrists above his head, kissing him furiously, their tongues caressing each other in a passionate and wet dance.  
A hand sneaked under their bodies and Kei parted the omega's knees, settling between them.  
The blond traced over the buldge on Tadashi's boxers, but passed by it and touched the slick-wet patch on the grey material.  
"Quite wet, aren't you? Should I even bother preparing you?", Kei asked, licking Tadashi's collarbones and heading with a patch of wet kisses and purple bruises towards his scent glands.  
"N-no, we're...", Tadashi's eyes rolled to the back of his head as he twitched under Kei, back arching beautifully.  
"We're g-good..."  
"Alright, my pretty omega...", Kei said, pecking Tadashi's cheek, getting up only to walk towards a drawer. The mewls of betrayal almost made him want to forget about anything else and just fuck the omega, but no. Tadashi was I heat, so he was the one who had to be responsible of Tadashi, had to take care of his boyfriend.  
The thought made Kei smile and, after having received a small tin-foil package from the drawer, Kei took careful steps towards the bed.

There was a warm feeling in his chest as Tadashi whimpered for him.

Settling between Tadashi's thighs again, the alpha stroked his hair softly, noting just how hot the omega was.  
"Do you want to go right now?", Kei asked teasingly, a crooked smirk on his face, tho it only served to make his intense eyes even darker.  
"Y-yes...", the omega moaned under his breath, pushing his chest out, as if to entice the alpha, and entice he did.  
Kei latched onto pink nipples, sucking one into his mouth and flicking the other with his free hand.  
Tadashi let out a string of moans and shrieks, which only encouraged the alpha to go harder onto the sensitive buds.  
With his other hand, Kei unbuckled his belt and unbuttoned his pants, pushing his own boxers down and freeing his member.  
Tadashi seemed to shake even harder as he noticed the alpha's cock, hard and leaking, knot already forming at the base.  
Kei kissed Tadashi again, softer this time, tongue running over kiss-bruised lips and soothing their soreness with gentle and wet touches.  
In the meantime, Kei rolled the condom onto himself, groaning at finally giving himself some relief.  
"Tadashi..."  
The brunet hummed.  
"Beg for me... Be a good omega and beg for your alpha's knot, will you?"

The omega gulped audibly, eyes tearing up in embarrassment, but flush intensifying, while his smaller member leaked on his soft, freckled stomach, where Kei's hand was resting, moving slowly, in small circles, almost encouragingly.  
"Please... Put it in, I-I... I want you inside, I w-want your knot to fill me up! Please, K-Kei...!", His sweet, high-pitched-with-arousal voice cracked a bit at the end, which only managed to arouse Kei even more.  
With a smirk, Kei slotted their lips together and finally brought his hips down, rubbing against the omega's slick entrance.  
After another whine, Kei entered the brunet below him, thrusting softly, as though Tadashi would break if he moved too quickly.

Tadashi liked,  _adored,_ the feeling of Kei's member inside of him, he did, but the other wasn't moving fast enough, not when Tadashi was this close. If he were to come like this, he'd lose a bit of his sanity along the way.  
"Kei, K-Kei, fas- hngh- faster!", Tadashi moaned loudly as Kei hit his sweet spot.  
The alpha let out another deep growl and grabbed Tadashi's knees, pushing down and bending the omega nearly in half.  
Kei started thrusting at an insane speed, and the new angle combined with the roughness of it all had the omega screaming, arms clinging to Kei's neck.  
Just a little bit,  _just a little bit more-_  
"Ahh, right th-there, please alpha, knot m-me!"  
And knot Kei did. After a few more thrusts at the breakneck pace the alpha had set, Tadashi was screaming out loud, muscles trembling and brain short-circuiting at the immense amount of pleasure. His cum splattered on to his own chest, a few strings hitting Kei's hard abdomen too  
Kei continued to move, faster than before, an action which turned Tadashi's oversensitive body into an erogenous spot, his hole clenching over the alpha's knot.  
"Tadashi-"  
Kei mouthed at the side of Tadashi's neck and, as he reached his orgasm, bit into the skin found there.  
Tadashi screamed again, throat raw and voice hoarse, a sheet of sweat making his lightly tanned and flustered body glow.

The blond collapsed on top of his lover, his...   
His mate.   
His omega.   
**His.**

Kei gathered the trembling omega into his arms, slowly and carefully moving Tadashi into his lap, his head resting on the alpha's chest while they waited for his knot to deflate.  
In the haze of their first time together and the instinct-controlled actions of the pair during Tadashi's heat, the following week passed into a blur of love-making and forced feedings on Tadashi's part, the omega refusing to eat and even drink sometimes, trying instead to rub himself against Kei's lap.  
It was a long week, and Kei would only later notice the mark, or rather the lack of it thereof.

 

* * *

 

 

Tadashi groaned, his whole body aching, limbs heavy and skin littered with bruises and bitemarks. Though the omega couldn't bring himself to dislike any of the markings, they hurt too good for such an  _opinion._  
But...  
There was one mark that made his stomach queazy with anxiety.  
The bonding mark on the side if his neck.  
Right now it was red and a bit purplish around the edges. It made his heart swell with a sort of pride, and he was. He was proud that Kei had thought that Tadashi deserved to be his mate, even if the brunet himself thought differently.

"Tadashi", Kei called from the kitchen. With a sigh, he got up and started to make his way towards their small kitchen, putting a smile on his face. He was still tired and he was sure the dark bags under his eyes looked as awful as ever.

As he entered the room, Tadashi was greeted with the smell of freshly baked waffles and Kei standing in front of the stove, shirtless, scratch marks on his back evident, yet healing.

"You don't usually cook, Kei, what's the ocasion?", Tadashi asked with a small grin stretching wider on his face.

"Well, it's for my mate, isn't it", he asked, still sleepy, yet witha hint of calm happiness in his voice.

At that, the omega gulped, a pang of guilt running through his stomach.

_ 'He... He doesn't mind...' _

The brunet looked at his intertwined fingers in his own lap, thumbs playing with the hem of his shirt.

"Tadashi?"

The aforementioned boy looked up, only to see Kei having stopped his meddling and put the utensils down, the stove now off and a plate p of steaming hot waffles on the counter.

"Can we talk?"

_'Oh no. Now that we've... Done it, he probably, he...'_

Tadashi took a deep breath. He needed to calm down, even if his throat seemed as dry as ever and if his eyes stung a bit. It almost felt as though he couldn't take enough air insidei his lungs at all the ideas his stupid,  _stupid_  brain was pushing fiorward, with seemingly no end.

"S-sure...", Tadashi whispered, if only to make the tremble in his voice less obvious.

Kei took a few steps and went to sit down on the chair next to Tadashi, reaching for the omega's hand, which seemed entirely too cold, especially compared to how heated his skin had been during his heat.

"I-is something wr-"

"Why didn't you mark me?", Kei snapped, voice lower than ususal, yet also barely above a whisper. Tadashi finally gathered the courage too look into Kei's eyes, only to see hurt and something almost akin to betrayal in those beautiful golden orbs.

"A-ah, well, I th-thought you... You...", Tadashi inhaled deeply, willing his body to stop actinga as if he was about to be atacked, but his breathing was speeding up and he couldn't stop his fingers from trembling, nor could he seem to keep his eyes on Kei's, lest he break down in front of the alpha.

Tadashi thought he came to terms with his own decision, but it seemed that he was too selfosh too even care about Kei and about how much he  _didn't deserve him whatsoever-_

 

Kei sighed and put both hands on the omega's shoulders, squeezing tightly, so he could bring Tadashi back to what was going on right now.

It hurt, it hurt to know that Tadashi wouldn't want to bond with him, but seeing him just stare blankly downwards and tears nearly falling from his green eyes, it was heartbreaking.

"Tadashi, please, calm down", he commanded softly, letting his own pheromones waft through the air, if only that would calm the omega down and stop his rising panic attack.

"I'm s-sorry...!", the boy cried out. "I can't... You desreve b-better than m-m-me!"

And that's when Kei's eyes widened. He looked at Tadashi, understanding finally flowing through his eyes.

"Look at me, love."

The omega sniffled lightly before raising his teary gaze to look at the blond.

Kei pulled Tadashi into his arms, letting the brunet muffle his quiet sobs into his bare chest, a bit of his heart breaking at the sight.

"Tadashi, we've been together for years now, haven't we?", he asked softly, trying to be comforting and not cold for once in his life.

"Y-yes...?"

Reaching a hand to run through brown locks of hair, Kei continued:

"And you, Yamaguchi Tadashi, are one of the most important people in my life."

"I-", Tadashi tried to object, but Kei interrupted him with a small chuckle.

"That was a statement, not a question, love."

Tadashi trembled even more after that and his sobs got louder, as though a dam had broken and the floodgates were now open. For how long... For how long had Tadashi doubted himself like this? And Kei hadn't even noticed.

He should have.

Goddamnit, he should've! He wanted to bond with the omega, yet this is how he showed his love?

 _Pathetic_ , Kei thought,  _pathetic indeed._

Without wasting another moment, Kei took Tadashi's face in his hands and brought their faces close enough that their foreheads were touching and their noses were brushing together.

"It's you that I want for the rest of my life", he whispered,whiping a few of Tadashi's tears away.

"M-me...?"

"You."

Tadashi looked almost incredulous, green eyes alight with a glimmer of hope.

"B-but... Why me...?"

A beat of silence.

"Because I love you more than anything else." 

 

**Author's Note:**

> This was requested by someone else and their headcannon was that once you are mated with someone, you can only have kids with them. Well I took that HC and fluffing ran with it
> 
> And I went just a biiiiiiit overboard. Like.  
> Just 6k words overboard.  
> (ಥvಥ)
> 
> Also, the ending was a bit too tusehs for my liking, but I have a limited amount of time on the PC so ¯\\_(ツ)_/¯


End file.
